This is just a huge crystal of smoky quartz of the fabulous quality, the quality the is the reason smoky quartz from the Urals is used for carvings. If this it did not have some (mostly natural) contacts, it could hold its own against a Swiss crystal that would cost a couple of grand. The clarity is just unbelievable, frankly optical-quality. But what makes it really interesting is that deep inside the crystal, impossible to photograph but very clear to the naked eye, are razor-sharp little crystals of gersdorffite (NiAsS), engulfed by the crystal as they grew after growing on the faces at earlier stages. If you were so inclined, you actually COULD carve this crystal into something really striking, with the gersdorffites showing inside! 17.2 x 11.2 x 10.7cm